Gas turbine exhaust silencers are designed for reliable operation during the cyclic and sustained elevated temperatures experienced by gas turbine exhaust systems used for power and compressor station applications. Constructed to provide maintenance free, long life, acoustic materials are contained to prevent settling and erosion that result in reduced acoustic performance and airflow in the structure that results in higher community noise, reduced performance and failure of the silencer. Silencers are provided for new projects and as a replacement of OEM gas turbine exhaust silencers for refurbishment and up-grade to existing gas turbine exhaust system silencers.